[Horizontal stress of abutment. Particularly regarding difference in removable partial denture design].

Prosthesis with removable partial denture is a daily clinical procedure for compensating the morphological loss and hypofunction of teeth and various gnathostomatic system. The removable partial denture not only comprises of many elements such as denture base, abutment and clasp but accordingly has to undergo morphologically complicated operative process, thus posing many factors concerning the functional stability coping with diverse masticatory motions. However, from the fact that retention and stability of the denture at it's functioning are obtained basically from it's connection with abutment, assessments in multiple aspects have been made regarding the influence exerted on abutment by difference in the structural elements, i. e. clasps, which transmit the movement of denture directly. There were the assessments by means of the displacement, measuring system by the use of microdial gage, stereoscopic camera, eddy currents transfer, and magnetic resistant element, and deformation measuring systems such as photoelasticity method, holography, moiré method and strain gage method. However, these systems are the methods for assessing abutment as subject but not the assessing system including all the basic structural elements of denture. Therefore, the author has made observation of the influence exerted on the dynamics of abutment by the difference between clasps in 2 kinds and by cross arch stabilization by designing aker's clasp and RPI clasp for the abutment by the use of cast frame standardized.(ABSTRACT TRUNCATED AT 250 WORDS)